Question

How do you simplify 8-4m-9+m?

Answer 1

Here, take all the variables together & all the constants together as follows:
8-4m-9+m
(8-9)+(-4m+m)
-1-3m

So, your final answer is -3m-1

Hope this helps!

Answer 2

-4m +m = -3m 
(m=1 because it the variable is alone than it would be just 1)
then you have -9 + 8 which is -1
so the answer would be -3m -1
hope I helped!